Fish passage apparatus with flow restriction and method

ABSTRACT

An improved fish passage apparatus is combined with hydroelectric power generation to facilitate migration of fish between water bodies of different heights with minimal injury or trauma to fish. It may also be optimized for power generation when fish are not moving through it. The fish passage apparatus comprises a connecting tube providing fluid communication between upper and lower water bodies, an upper valve in the connecting tube adapted to control flow of water to or from an upper water body, a lower valve in the connecting tube adapted to control flow of water to or from a lower water body, and a working tube opening into the connecting tube between the upper and lower valves a working portion of which extends functionally vertical to above a water level of the upper body of water and to below a water level of the lower body and is vented at its top such that water can flow freely in and out of the working portion. The working tube contains a means for restricting flow thereby increasing the safety to fish passing through the connecting tubes.

This application is a continuation in part of that certain applicationfiled May 8, 2009 under application Ser. No. 12/437,738 now U.S. Pat.No. 8,011,854 and claims the benefit thereof.

BACKGROUND

1. Field of the Invention

This invention relates to tubes connected between two bodies of water ofdifferent elevations optimized for power generation, and morespecifically to such a configuration adapted for fish migration betweenthe bodies of water.

2. Prior Art

It is well known that power generators between bodies of water ofdifferent heights extract potential energy from the flow of water.Hydropower generation systems typically rely on water flow from damsthrough turbines that run generators. However, turbine based systems donot allow for fish migration beyond the dams or often injure fishpassing through them. To avoid injury and death to fish passing dams,high cost systems are employed. Currently, the primary bypass methodsare a series of pools as fish ladder apparatus for upstream migrationand spillways for downstream migration. Unfortunately, these methods arealso problematic due to passage delays, increases in dissolved gasses,fish de-scaling, fish disorientation, increased predation, injury and soforth. Further, they are only effective with head heights less thanabout 90 feet. For dams with a head of more than 90 feet, fish must betrapped and transported around or lifted over the dam due to excessivemortality rates and the inability of fish to completely climb theladders.

It is an object of the present invention to provide a combination fishpassage apparatus and hydropower generator that is conducive to fishmigration with the least possible injury or trauma to the fish. It isanother object that the combination be economically effective for headheights ranging from very small to very large. It is still anotherobject that extraction of potential energy of the water between twobodies of water of different heights be optimized.

SUMMARY

These objects are achieved in the combination fish passage apparatus andpower generator through an oscillating column of water as describedherein which provides a connecting tube between two bodies of water witha pair of valves controlling water flow at the upper and lower bodies ofwater. When the upper valve is opened water surges from the upper bodyof water having significant potential energy in its momentum. To capturethat energy a working tube, functionally vertical, is connected to theconnecting tube between the valves. Flow of water to the lower body ofwater is interrupted with the lower valve closed thereby directing flowinto the working tube. The momentum of the flow causes an overshoot ofthe water level in the working tube past the water level of the upperbody of water by 50 percent or more before it falls back and then risesagain in a wave-like decaying motion until eventually it equalizes atthe water level of the upper body of water. That higher water level inthe working tube may be captured by quickly closing the upper valve,thereby creating a head relative to the water level of the lower waterbody greater than that between the two bodies of water. The lower valveis then opened and the sudden release of water from the working tubecauses the water level in the working tube to drop below the water levelof the lower body of water in a similar wave-like decaying motion untilthe working tube water level equalizes with that of the lower body ofwater. Once the proper water level in the working tube is achieved, thenthe lower valve is closed and the upper valve can be opened again tostart another cycle.

One or more power generation systems (hereinafter “generator” includingall supporting structures and apparatus') are installed to operate incooperation with the movement of the water in the working tube such thatthe generator may operate in the normal manner of an electricitygenerator as that water moves through a traditional generator. For thesepurposes, use of the term ‘generator’ is deemed to include any and allpower takeoff mechanisms to convert water flow to rotation of atraditional generator, movement of a linear generator, movement of apoint absorber, movement of air above the water as in a water piston, orother means for extracting energy such as piezoelectric devices,hydraulic and/or other weight induced generators, and turbines incombination with traditional electric generators, etc.

For a traditional generator, when the lower valve is opened quickly,water from the working tube surges out. It is that flow that operatesthe generator. All or virtually all of the potential energy captured inthe working tube is extracted ideally when there is no or minimal flowto the lower water body, that is, all momentum from the initial surgefrom the working tube is extracted by the generator when the water levelin the working tube reaches the water level of the lower body of water.Necessarily, for a traditional generator, the generator should be belowthe level of the lower water body and the working tube extends below thewater level of the lower body of water. For a traditional generator itmay also be important to rectify the water flow so that the back-flowingwater does not flow against the turbine and potentially cause damage. Byrectifying the bidirectional flow into a unidirectional flow, the risingsurge in addition to the falling surge in the working tube will spin thegenerator. Although, by extracting energy from the surge as it rises orfalls will ensure that the overshoot, if any, is minimal.

For other technologies that may be employed, the generator may belocated as appropriate relative to the water flow and surge, which aredeemed included in this representative description. That is, it isrecognized that although this description is given in terms of watermoving to the lower body of water, however, it should be understood thatenergy can also be extracted from water surging upwards into the workingtube from the upper water body by suitably operating the upper and lowervalves. These and all other manner of extracting potential energy fromthe upper body of water being at an elevation above the lower body ofwater are deemed included in the present description, which is deemedrepresentative of all other such manner.

Valves of any appropriate design are suitable. Such valves may be basedon butterfly, knife, slide, gate and diaphragm mechanisms for example,or any other and may be operated pneumatically, electrically, etc. oreven manually. All are deemed included herein as possible mechanisms.

It is understood that when a traditional generator is not operating toextract energy from the working tube water flow, the surge of water outof the working tube when the lower valve is opened while the upper valveis closed will cause an overshoot downward past the water level of thelower body of water similar to the overshoot upward in the working tubeabove the upper body of water as described previously. That lower levelcan be captured by quickly closing the lower valve. This lower levelwill then be the effective lower level when the upper valve is openedwhich will cause an even greater overshoot in the working tube upwardpast the upper water body level. This cycle can be repeated until thereis a maximum head in the working tube.

It is understood that this invention may be well implemented asproviding an improved method of fish migration between two bodies ofwater, upstream and or downstream. In this implementation, it isimportant that the valves be opened and closed in such a manner as tonot injure the fish. Experimentation has shown that this will likelyrequire the valves to open and close less quickly, which will compromiseto some extent the advantage described above in power generation. Asillustrated in the figures, the fish will pass through the connectingtube between the valves without passing into the working tube. In fact,a screen or other device will be installed to prevent fish from enteringthe working tube thereby ensuring that fish are never in danger from apower takeoff system. In addition, portions of the connecting tube mayalso serve as resting places during fish passage.

Downstream migrating fish, during the first half of the cycle when thelower valve is closed and the upper valve opens allowing water to surgethrough the top-half of the connection tube, down through the fishscreen, and into the working tube, simply drift with the current down tothe fish screen. After arriving at the fish screen, the fish pass to thelower half of the connection tube, which during the first half of thecycle is still and has no motion. Fish that did not pass the fish screenbefore the working tube crests will then be forced back up theconnection tube towards the upper valve as the falling level in theworking tube will cause surging water to move back up the connectiontube. This back and forth motion will occur as long as the motion in theworking tube is not stopped by closing the upper valve. Once the uppervalve is closed the motion will cease. Next, the second half of thecycle begins as the lower valve is opened. Water from the working tubewill surge out of the working tube, out through the fish screen and downthe lower half of the connection tube and out the lower valve carryingany fish in that area along with it. The lower valve is then closed andthe cycle can begin again.

Upstream migrating fish need to swim past the lower valve while it isopen during the second half of the cycle. As fish pass through the valveand into the lower connection tube against the current, the valve closesand the current stops while the fish continue towards the area of thefish screen. After passing the fish screen, the fish will be eitherpushed back towards the fish screen area or pushed upward toward theupper valve depending on the motion in the working tube. The wholeupstream passage should take seconds or minutes instead of the hours ordays currently required.

Energy generated from the water flow in the working tube can provideelectrical energy to operate the valves and provide for other uses. Fishmay be encouraged into, through and out of the tubes by any of variouseffective methods, such as use of light, slope of the connecting tube,water flow, etc.

Juvenile fish are hardy in many respects but also very fragile also. Oneinstance of harm to which juvenile fish are fragile is sudden changes inpressure. In many lakes the fish are require to travel through generatorturbines in the dam to get down stream. These turbines can turn slowlyenough not to harm the fish from contact with the fish physically butthey still harm the fish. The turbines create a zone of high pressure onit leading edge. When juvenile fish swim through this high pressurezone, the sudden change damages their swim bladder, other internalorgans or become easier prey.

It is the object of this invention to provide a fish passage apparatusthat maintains a near constant flow and pressure on the fish or to onlyallow flows and pressure changes that are within a healthy range asdetermined by experts. Although, opening and closing the upper and lowervalves quickly to gain the effect of water hammer or fluid inertia willgenerate more electricity; it may also cause pressure spikes and flowfluctuations that can be harmful to the fish by scaring them away orcausing the water to flow too fast to swim up. To prevent the pressureor flow in the connecting tubes from changing too rapidly a means forrestricting the flow will be introduced into the working tube. The flowcan be restricted by having a variable valve in the working tube thatopens wider as flows decrease and closes as flows increase to maintain anear constant flow rate. Another means for restricting flow can bechanging the diameter of the working tube entirely. A larger workingtube would allow the water to flow for a longer time and have decreasedback pressure therefore less pressure could build in the connectingtubes. A smaller diameter working tube would decrease fluid flow in theconnecting tube therefore, increasing the velocity of the water flowinginto the working tubes and magnifying the effect of water hammer orfluid inertia. In most instances the means for generating electricityfrom the water in the working tube will pull most of the energy out ofthe flowing water and will be a flow restrictor in itself.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of a fish passage apparatus for control of waterflow that facilitates fish migration between two bodies of water ofdifferent heights, including a working tube that generates power incooperation with a power generator and contributes to moving fishbetween the bodies of water.

FIG. 2 is a diagram showing a plurality of fish passage apparatus ofFIG. 1 connected in series.

FIG. 3 is a diagram showing the fish passage apparatus of FIG. 1 adaptedto optimize power generation instead of fish migration with the waterlevel in the working tube at the water level of the lower body of water.

FIG. 4 is a diagram showing the fish passage apparatus of FIG. 1 adaptedto optimize power generation instead of fish migration with the waterlevel in the working tube at the water level of the overshoot from watersurging from the upper body of water.

FIG. 5 is a diagram showing the fish passage apparatus of FIG. 1 adaptedto optimize power generation instead of fish migration with the waterlevel in the working tube at the water level of the downward overshootfrom water surging out of the working tube when the valve at the lowerbody of water is opened quickly.

FIG. 6 is a diagram showing a plurality of power generators of FIG. 3connected in series.

FIG. 7 is a diagram of a fish passage apparatus for control of waterflow that facilitates fish migration between two bodies of water ofdifferent heights, including a working tube that generates power incooperation with a power generator and contributes to moving fishbetween the bodies of water and has an enlarged diameter working tube todecrease pressure.

FIG. 8 is a diagram of a fish passage apparatus with a smaller diameterworking tube for decreasing the flow of water in the connecting tube andworking tube.

FIG. 9 is a diagram of a fish passage apparatus with a flow restrictorin the working tube to prevent rapid accelerations and pressure changesin the fluid of the connecting tube and working tube.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in FIG. 1, the fish passage apparatus 10 of the presentinvention for fish passage between water bodies 12, 14 of differentheights with different water levels 16, 18 comprises a connecting tube20 providing fluid communication between upper and lower water bodies12, 14, an upper valve 22 in the connecting tube 20 adapted to controlflow of water to or from the upper water body 12, a lower valve 24 inthe connecting tube 20 adapted to control flow of water to or from thelower water body 14, and a working tube 26 containing a column of water28 with a surface level 38 opening into the connecting tube 20 betweenthe upper and lower valves 22, 24 a working portion of which workingtube 26 extends functionally vertical to above the water level 16 of theupper water body 12 and to below the water level 18 of the lower waterbody 14 and is vented at its top such that water can flow freely in andout of the working tube 26. A screen 30 covers the opening 32 of theworking tube 26 at the junction of tubes 20, 26 such that fish areprevented from leaving connection tube 20 and entering the working tube26.

When the upper valve 22 is opened with the lower valve 24 closed, waterflows through the connecting tube 20 and flows into the working tube 26raising the surface level 38 of the water column 28 to at least thewater level 16 of the upper body of water 12 and allows for fish toenter the connecting tube 20 from the upper body of water 12. When theupper valve 22 then closes and the lower valve 24 opens, fish may flowwith the current from the connecting tube 20 into the lower body ofwater 14 as the surface level 38 of the water column 28 in the workingtube 26 lowers to at least the water level 18 of the lower body of water14. Whereupon, the lower valve 24 closes and a new cycle can begin againwith the opening of upper valve 22.

An electrical power generator 34 operates in cooperation with theworking tube 26, adapted to extract potential energy from the column ofwater 28 in the working tube 26 as the upper and lower valves 22, 24 aresuitably operated; which, for example of a traditional generator, as thecolumn of water 28 falls when the upper valve 22 is closed while thelower valve 24 is opened, or but also alternatively when the upper valve22 is opened while the lower valve 24 is closed and the column of water28 rises.

Clearly, a plurality of said fish passage apparatus 10 may be combinedin series where an upper body of water 12 of one of said plurality offish passage apparatus 10 is a lower body of water 14 of a next higherfish passage apparatus until the final upper body of water 12 isreached, as shown in FIG. 2.

As shown in FIG. 3, the power generator 34 may be used withoutconsideration for fish migration between the two bodies of water, thatis, with or without accommodations for fish migration, the primarydifference being the rate at which the valves 22, 24 open and close andthe slope of the connecting tube 20. For power generation, the surfacelevel 38 of the column of water 28, or head, may be maximized. Tomaximize the head in the column of water 28, the upper valve 22 is suchas can be opened sufficiently quickly to result in a surge of water intothe working tube 26 such that momentum in said surge of water results ina surface level 38 of the column of water 28 in the working tube 26 thatextends upward typically beyond a water level 16 of the upper body ofwater 12. Similarly, the upper valve 22 is such as may be closedsufficiently quickly to capture and maintain the column of water 28 inthe working tube 26 at a desired upper level 36, as shown in FIG. 4. Aswith the upper valve 22, the lower valve 24 is such as may be closedsufficiently quickly to capture and maintain the column of water 28 inthe working tube 26 at a desired lower level 40 after the lower valve 24is opened with the upper valve 22 closed resulting in a surge of waterout of the working tube 26, which desired lower level 40 may be belowthe water level 18 of the lower body of water 14, as shown in FIG. 5.

As shown in FIG. 6, as with the fish passage apparatus configuration, aplurality of said power generators also may be combined in series wherean upper body of water 12 of one of said plurality of power generators34 is a lower body of water 14 of a next higher power generator untilthe final upper body of water 12 is reached.

In use then, electrical power may be generated from potential energybetween upper and lower bodies of water 12, 14 and maximized byproviding the configuration described above and appropriately quicklyopening and closing the upper and lower valves 22, 24 to create andexploit momentum of water flowing into and out of the working tube 26.The cycle of opening and closing the valves 22, 24 as described is thenrepeated for continual power generation. Power generated may by used tooperate the valves and for other purposes. When the configuration isadditionally, or solely, used for fish migration between the bodies ofwater, the speed of the opening and closing of the valves may be reducedto prevent injury to the fish.

As further shown in FIG. 7, the fish passage apparatus 10 of the presentinvention for fish passage between water bodies 12, 14 of differentheights with different water levels 16, 18 comprises a connecting tube20 providing fluid communication between upper and lower water bodies12, 14, an upper valve 22 in the connecting tube 20 adapted to controlflow of water to or from the upper water body 12, a lower valve 24 inthe connecting tube 20 adapted to control flow of water to or from thelower water body 14, and an enlarged working tube 56 containing a columnof water 28 with a surface level 38 opening into the connecting tube 20between the upper and lower valves 22, 24 a working portion of whichenlarged working tube 56 extends functionally vertical to above thewater level 16 of the upper water body 12 and to below the water level18 of the lower water body 14 and is vented at its top such that watercan flow freely in and out of the enlarged working tube 56. Enlargedworking tube 56 is of an increased diameter set for the height of thewater level 16 of the upper water body 12 to prevent the wateracceleration or changes in water pressure that would be dangerous to thefish. A screen 30 covers the opening 32 of the working tube 26 at thejunction of tubes 20, 56 such that fish are prevented from leavingconnection tube 20 and entering the enlarged working tube 56. When theupper valve 22 is opened with the lower valve 24 closed, water flowsthrough the connecting tube 20 and flows into the enlarged working tube56, slowly raising the surface level 38 of the water column 28 to atleast the water level 16 of the upper body of water 12 and allows forfish to enter the connecting tube 20 from the upper body of water 12.When the upper valve 22 then closes and the lower valve 24 opens, fishmay flow with the current from the connecting tube 20 into the lowerbody of water 14 as the surface level 38 of the water column 28 in theenlarged working tube 56 lowers to at least the water level 18 of thelower body of water 14. Whereupon, the lower valve 24 closes and a newcycle can begin again with the opening of upper valve 22. An electricalpower generator 34 operates in cooperation with the enlarged workingtube 56, adapted to extract potential energy from the column of water 28in the enlarged working tube 56 as the upper and lower valves 22, 24 aresuitably operated; which, for example of a traditional generator, as thecolumn of water 28 falls when the upper valve 22 is closed while thelower valve 24 is opened, or but also alternatively when the upper valve22 is opened while the lower valve 24 is closed and the column of water28 rises.

As further shown in FIG. 8, the fish passage apparatus 10 of the presentinvention for fish passage between water bodies 12, 14 of differentheights with different water levels 16, 18 comprises a connecting tube20 providing fluid communication between upper and lower water bodies12, 14, an upper valve 22 in the connecting tube 20 adapted to controlflow of water to or from the upper water body 12, a lower valve 24 inthe connecting tube 20 adapted to control flow of water to or from thelower water body 14, and a constricted working tube 66 containing acolumn of water 28 with a surface level 38 opening into the connectingtube 20 between the upper and lower valves 22, 24 a working portion ofwhich constricted working tube 66 extends functionally vertical to abovethe water level 16 of the upper water body 12 and to below the waterlevel 18 of the lower water body 14 and is vented at its top such thatwater can flow freely in and out of the constricted working tube 66.Constricted working tube 66 is of decreased diameter set for the heightof the water level 16 of the upper water body 12 to prevent the waterflow rate from being too high or changes in water pressure that would bedangerous to the fish. A screen 30 covers the opening 32 of the workingtube 26 at the junction of tubes 20, 66 such that fish are preventedfrom leaving connection tube 20 and entering the constricted workingtube 66.

As further shown in FIG. 9, a means for restricting the flow of thecolumn of water 28 is placed in the working tube 26. The means forrestricting flow is a flow restriction valve 76 that is preferably apressure compensating valve that allows more flow as pressure increasesthereby maintaining a near constant pressure. Another preferable flowrestriction valve 76 would regulate flow to maintain a constant flowthereby preventing fluid accelerations.

Having described the invention, what is claimed is as follows:
 1. A fishpassage apparatus for fish passage between water bodies of differentheights, comprising, a connecting tube providing fluid communicationbetween upper and lower water bodies, an upper valve in the connectingtube adapted to control flow of water to or from an upper water body, alower valve in the connecting tube adapted to control flow of water toor from a lower water body, a working tube opening into the connectingtubes between the upper and lower valves, a working portion of whichextends functionally vertical to above a water level of the upper bodyof water and to below a water level of the lower body and is vented atits top such that water can flow freely in and out of the workingportion, a means for restricting flow into or out of the working tubesand connecting tube.
 2. The fish passage apparatus of claim 1 whereinfish are prevented from entering the working tube from the connectingtube.
 3. The fish passage apparatus of claim 1 wherein with the lowervalve closed, when the upper valve is opened water flows through theconnecting and working tubes raising the water surface level in theworking tube to at least the water level of the upper body of water andfish can enter and exit the connecting tube from the upper body of waterwhile the upper valve is open, and when the upper valve then closes andthe lower valve opens, fish may enter and exit the connecting tubethrough the lower valve as the water in the working tube lowers to awater level of at least that of the lower body of water.
 4. The fishpassage apparatus of claim 1 wherein with the upper valve closed, whenthe lower valve is opened water flows out of the working tube to atleast the water level of the lower body of water and fish can enter theconnecting tube from the lower body of water and when the lower valvethen closes and the upper valve opens, fish may swim upstream throughand out of the connecting tube into the upper body of water.
 5. The fishpassage apparatus of claim 1 further comprising an electrical powergenerator operating in cooperation with the working tube adapted toextract potential energy from a column of water in the working tube asthe column of water moves when the upper and lower valves are suitablyoperated.
 6. The fish passage apparatus of claim 1 wherein, the meansfor restricting flow into or out of the working tube and connecting tubeis a constricted diameter working tube.
 7. The fish passage apparatus ofclaim 1 wherein, the means for restricting flow into or out of theworking tube and connecting tube is an enlarged diameter working tube.8. The fish passage apparatus of claim 1 wherein, the means forrestricting flow into or out of the working tube is a restricting valve.9. The fish passage apparatus of claim 8 wherein, the restricting valveis a pressure compensating valve that allows more flow as pressureincreases thereby maintaining a near constant pressure.
 10. The fishpassage apparatus of claim 8 wherein, the restricting valve is flowregulating valve that regulates flow to maintain a constant flow therebypreventing fluid accelerations.
 11. The fish passage apparatus of claim1 comprising a means for restricting pressure into or out of the workingtube.
 12. The fish passage apparatus of claim 11 wherein, the means forrestricting pressure into or out of the working tube is an enlargeddiameter working tube.
 13. A method of providing a fish passage betweenupper and lower bodies of water, comprising the following steps: a.providing a connecting tube that provides fluid communication betweenupper and lower water bodies, an upper valve in the connecting tubeadapted to control flow of water to or from an upper water body, a lowervalve in the connecting tube adapted to control flow of water to or froma lower water body, a working tube opening into the connecting tubebetween the upper and lower valves a working portion of which extendsfunctionally vertical to above a water level of the upper body of waterand is vented at its top; b. with the upper and lower valves closed,opening the upper valve and water flowing in at a reduced rate due to ameans for restricting fluid flow within the working tube and thereinestablishing an upper fish migration condition during which conditionfish may swim upward through the connecting tube and into the upper bodyof water and fish may swim from the upper body of water into theconnecting tube; c. closing the upper valve to end the upper fishmigration condition and maintain the column of water at a desired upperlevel in the working tube; d. with the upper valve closed, opening thelower valve to allow water to flow out of the working tube at a reducedrate due to a means for restricting fluid flow within the working tube,with the water level in the working tube stabilizing at the water levelof the lower body of water therein establishing a lower fish migrationcondition wherein, the fish may swim downward through the connectingtube and into the lower body of water and fish may swim from the lowerbody of water into the connecting tube; e. maintaining the lower fishmigration condition a desired period of time to allow fish migratingdownstream to exit the connection tube at its lower end or to allow fishmigrating upstream to enter the connection tube at its lower end; f.closing the lower valve; g. repeating steps a through f.
 14. The methodof claim 13 with the additional step of generating electrical power fromthe movement of the water in the working tube.
 15. The method of claim14 wherein electrical power is generated from upward movement of thewater in the working tube or from downward movement of the water in theworking tube or both.
 16. The method of claim 13 wherein, the workingtube has a means for restricting pressure instead of a means forrestricting flow.